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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package com.oracle.graal.pointsto.standalone.meta;

import com.oracle.graal.pointsto.meta.AnalysisField;

import jdk.graal.compiler.core.common.spi.ConstantFieldProvider;
import jdk.graal.compiler.core.common.spi.JavaConstantFieldProvider;
import jdk.graal.compiler.nodes.spi.CanonicalizerTool;
import jdk.vm.ci.meta.MetaAccessProvider;
import jdk.vm.ci.meta.ResolvedJavaField;

public class StandaloneConstantFieldProvider extends JavaConstantFieldProvider {

    private final ConstantFieldProvider originalConstantFieldProvider;
    /**
     * In the default standalone mode configuration, this field is set to false and all classes are
     * runtime initialized. We take all fields as not final, so that it doesn't read field value
     * from current environment. Test com.oracle.graal.pointsto.test.ConstantFieldTest verifies this
     * method.
     **/
    private final boolean foldFinalFields;

    public StandaloneConstantFieldProvider(MetaAccessProvider metaAccess, ConstantFieldProvider originalConstantFieldProvider, boolean foldFinalFields) {
        super(metaAccess);
        this.originalConstantFieldProvider = originalConstantFieldProvider;
        this.foldFinalFields = foldFinalFields;
    }

    @Override
    public <T> T readConstantField(ResolvedJavaField f, ConstantFieldTool<T> tool) {
        AnalysisField field = (AnalysisField) f;

        /*
         * Ideally, we would mark the type as reachable only when the field is final or stable,
         * i.e., there is an actual chance of constant folding it. But for the purpose of the
         * analysis tests, it does not matter if we mark a few types too many as reachable.
         */
        field.getDeclaringClass().registerAsReachable(field);

        T foldedValue = originalConstantFieldProvider.readConstantField(field.wrapped, tool);
        if (foldedValue != null) {
            field.registerAsFolded(tool.getReason());
        }
        return foldedValue;
    }

    @Override
    public boolean isTrustedFinal(CanonicalizerTool tool, ResolvedJavaField field) {
        return foldFinalFields && originalConstantFieldProvider.isTrustedFinal(tool, field);
    }

    @Override
    public boolean isFinalField(ResolvedJavaField field, ConstantFieldTool<?> tool) {
        return foldFinalFields && super.isFinalField(field, tool);
    }
}
